Laminectomy rongeurs are used by neurosurgeons and orthopedic surgeons for cutting disks or other spinal bone structures. In general, these instruments are designed to clamp and sever small segments of bone structure in a nibbling or biting-like procedure. Thus, in performing these cutting tasks, surgeons frequently encounter difficult sections which require the wiggling or twisting of the instruments. This movement places a great deal of strain on these rongeurs which frequently damages them. In conventionally styled rongeurs, the damage often involves the snapping of the lower bar near its tip. Additionally, the rongeur edges frequently roll over and are dulled even if the tip does not fracture the cutting edges as a result of forces applied from the twisting and wiggling movement.
The fracturing of the tip and the dulling of the edges in these conventional rongeurs is a direct result of the particular construction of the rongeurs heretofore used. These constructions are such that the two bars or jaws that are the major components of forming the rongeurs are often secured together by a double pivot which causes non-parallel movement of the bars during use. In addition, the inherent weakness of conventional rongeurs is also partially due to the mechanism of the upper and lower bars that permits one bar to slide relative to the other as well as to construction at the cutting tip of the instrument.
Cutting fragments, bones, soft tissue, and ligamentum fiavum are often caught in the cutting edge of the upper bar forming the rongeurs. This debris must be removed prior to another use of the rongeurs. Frequently, the surgeon uses a second rongeurs while the first is being cleaned of debris in the cutting edge by a nurse.